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Finding the Fourth Proportional to 485.69, 669.96 and 308.31

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Solution

The fourth proportional to 485.69, 669.96 and 308.31 is: 425.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.69 : 669.96 = 308.31 : x
  2. Step 2: Convert to fraction form
    485.69/669.96 = 308.31/x
  3. Step 3: Cross multiply
    485.69x = 669.96 × 308.31
  4. Step 4: Simplify right side
    485.69x = 206,555.37
  5. Step 5: Solve for x
    x = 206,555.37/485.69
  6. Step 6: Final answer
    x = 425.29

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.